title: Stable label-free fluorescent sensing of biothiols based on ThT direct inducing conformation-specific G-quadruplex.
abstract: In this work, a new, label-free, turn-on fluorescent sensor for biothiols detection based on ThT direct inducing conformation-specific G-quadruplex is developed. The sensing approach is based on a conformational switch of oligonucleotide controlled by Hg(2+) and a commercially available water-soluble fluorescent dye, Thioflavin T (ThT). A noticeable fluorescence light-up in ThT on binding to the G-quadruplex grants the sensor excellent sensitivity. The specific quadruplex conformation induced directly by ThT and pronounced structural selectivity of ThT for G-quadruplexes could generate more stable luminescence and make sure high specificity in complex biological samples. The present assay allows for the selective determination of cysteine and glutathione in the range of 2.0 × 10(-8)-2.5 × 10(-6)M and 3.0 × 10(-8)-2.0 × 10(-6)M with a detection limit of 8.4 nM and 13.9 nM respectively. The diagnostic capability and potential in practical applications of this method have been demonstrated by detecting biothiols in human blood serum.
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Engineering Research Center of Pesticide and Medicine Intermediate Clean Production, , Shandong Normal University, Jinan 250014, PR China.
authors.forename: Li-li
authors.initials: LL
authors.lastname: Tong
authors.forename: Lu
authors.initials: L
authors.lastname: Li
authors.forename: Zhenzhen
authors.initials: Z
authors.lastname: Chen
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.forename: Bo
authors.initials: B
authors.lastname: Tang
mesh_terms: D052160:Benzothiazoles; D015374:Biosensing Techniques / Q000379:methods*; D003545:Cysteine / Q000097:blood*; D005456:Fluorescent Dyes / Q000737:chemistry*; D054856:G-Quadruplexes; D005978:Glutathione / Q000097:blood*; D006801:Humans; D057230:Limit of Detection; D013050:Spectrometry, Fluorescence / Q000379:methods; D013844:Thiazoles / Q000737:chemistry*
chemical_list: D052160:Benzothiazoles; D005456:Fluorescent Dyes; D013844:Thiazoles; C009462:thioflavin T; D005978:Glutathione; D003545:Cysteine
keywords: Biothiols; Fluorescent sensing; G-quadruplex; Mercury ions; Thioflavin T (ThT)